I hate writing reviews as I believe everyone should listen for themselves. Measurements mean the design works, other people's opinions mean that's what they think. Only you can tell for yourself.
But, since more than one person asked, here's the story.
I am a former high-end 2-channel snob, having recently liquidated a system I spent more than the cost of some houses on. I sold everything because as I got older I seldom used it, and we returned the dedicated room to its original intent as a third bedroom. This meant I was down to two systems: the HT system in the living room, and my headphone/2-channel setup in my office. In the living room HT I replaced the CD player and DAC I was using with a 2016 vintage Gungnir MB DAC being fed from a Elac Discovery Roon end point via coax S/PDIF. This sends analog out to an Anthem pre/pro and then to the amps and my HT speakers (DIY open-baffle system I designed and built myself.) This setup was great for casual 2-channel music, such as listening while surfing the web on a Sunday morning or putting on the occasional playlist streaming from my server as glorified background music. I seldom do what might be called "critical listening" these days having out-grown that need years ago (no slam intended to those who enjoy this activity). When I want to listen more intimately I'll use my higher-end headphone system described in my sig line.
In any case, the problem with the Gungnir was always that it only came in silver when I purchased it. It's the only silver component in my HT rack and it visually stood out like a sore thumb. It sounded great, better than the Wavelength Brick it replaced, so I bought some adhesive-backed flat black vinyl and covered the front so it was no longer noticeable. It was a great solution.
When the new 2/64 Bifrost was announced, it intrigued me. I always appreciate the newest designs from the Schiit team as I like supporting innovative audio engineering. Plus Bifrost was a more appealing form factor than Gungnir in my HT rack application, and it came in black. I bought one and swapped it into the system.
First impressions, described in an earlier post, was that the Bifrost was brighter, more dynamic and had a higher output level, where the Gungnir was much darker sounding and seemed to have a bass-emphasis that the Bifrost did not. I liked the overall balance much more. The brighter, more "clinical" sound appealed. I left it in.
Now it's been a couple weeks and I find myself turning on the system more often to listen to music. I attribute this to the Bifrost as the only difference in the system. I'll keep it.
For those who care about such things, the cables being used are a Nordost digital coax between source and DAC and Better Cables Silver Serpents RCA cables between the DAC and the preamp. The pre is driving Butler and Sunfire amplifiers through some Audioquest cables I had laying around. My loudspeakers are OB 3-ways of my own design using woofers I helped develop from consulting in the loudspeaker industry, CSS FR125 mids and RAAL ribbon tweeters with my design passive Xovers. The system has dual Adire Shiva subs in the front that are active all the time and 4X Acoustic Elegance IB15's in an IB installation in the ceiling that I turn on for loud movies. All the subs are driven by their own DIY Hypex class D amps that I built.
Bottom line, enjoy the music. I am enjoying the Bifrost.